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/*************************************************************************\
* Copyright (C) Michael Kerrisk, 2018. *
* *
* This program is free software. You may use, modify, and redistribute it *
* under the terms of the GNU General Public License as published by the *
* Free Software Foundation, either version 3 or (at your option) any *
* later version. This program is distributed without any warranty. See *
* the file COPYING.gpl-v3 for details. *
\*************************************************************************/
/* Listing 57-6 */
/* ud_ucase_sv.c
A server that uses a UNIX domain datagram socket to receive datagrams,
convert their contents to uppercase, and then return them to the senders.
See also ud_ucase_cl.c.
*/
#include "ud_ucase.h"
int
main(int argc, char *argv[])
{
struct sockaddr_un svaddr, claddr;
int sfd, j;
ssize_t numBytes;
socklen_t len;
char buf[BUF_SIZE];
sfd = socket(AF_UNIX, SOCK_DGRAM, 0); /* Create server socket */
if (sfd == -1)
errExit("socket");
/* Construct well-known address and bind server socket to it */
/* For an explanation of the following check, see the erratum note for
page 1168 at http://www.man7.org/tlpi/errata/. */
if (strlen(SV_SOCK_PATH) > sizeof(svaddr.sun_path) - 1)
fatal("Server socket path too long: %s", SV_SOCK_PATH);
if (remove(SV_SOCK_PATH) == -1 && errno != ENOENT)
errExit("remove-%s", SV_SOCK_PATH);
memset(&svaddr, 0, sizeof(struct sockaddr_un));
svaddr.sun_family = AF_UNIX;
strncpy(svaddr.sun_path, SV_SOCK_PATH, sizeof(svaddr.sun_path) - 1);
if (bind(sfd, (struct sockaddr *) &svaddr, sizeof(struct sockaddr_un)) == -1)
errExit("bind");
/* Receive messages, convert to uppercase, and return to client */
for (;;) {
len = sizeof(struct sockaddr_un);
numBytes = recvfrom(sfd, buf, BUF_SIZE, 0,
(struct sockaddr *) &claddr, &len);
if (numBytes == -1)
errExit("recvfrom");
printf("Server received %ld bytes from %s\n", (long) numBytes,
claddr.sun_path);
for (j = 0; j < numBytes; j++)
buf[j] = toupper((unsigned char) buf[j]);
if (sendto(sfd, buf, numBytes, 0, (struct sockaddr *) &claddr, len) !=
numBytes)
fatal("sendto");
}
}
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